Initial experience with the treatment of neurogenic detrusor overactivity with a new β-3 agonist (mirabegron) in patients with spinal cord injury.

STUDY DESIGN: It is a retrospective chart analysis.

OBJECTIVES: In patients with neurogenic lower urinary tract dysfunction (NLUTD) due to spinal cord injury (SCI), neurogenic detrusor overactivity (NDO) can cause both deterioration of the upper urinary tract and urinary incontinence. Antimuscarinic treatment is frequently discontinued due to side effects or lack of efficacy, whereas injection of onabotulinumtoxin into the detrusor is a minimally invasive procedure with risks of urinary retention, infection and haematuria. Mirabegron, a new β-3 agonist, is a potential new agent for treatment of NDO. Aim of the study was to evaluate the efficacy of mirabegron in SCI patients with NLUTD.

SETTING: Swiss Paraplegic Center, Nottwil, Switzerland.

METHODS: A retrospective chart analysis of SCI patient treated with mirabegron.

RESULTS: Fifteen patients with NDO were treated with mirabegron for a period of at least 6 weeks. Significant reduction of the frequency of bladder evacuation per 24 h (8.1 vs 6.4, P=0.003), and of incontinence episodes per 24 h (2.9 vs 1.3, P=0.027) was observed. Furthermore, we observed improvements in bladder capacity (from 365  to 419 ml), compliance (from 28 to 45 ml cm(-1) H(2)0) and detrusor pressure during storage phase (45.8  vs 30 cm H(2)0). At follow-up, 9/15 patients were satisfied with the therapy, 4/15 reported side effects (3 × aggravation of urinary incontinence, 1 × constipation).

CONCLUSIONS: Mirabegron may evolve as an alternative in the treatment of NDO. We observed improvements in urodynamic and clinical parameters. Due to the limited number of patients and the retrospective nature of the study, prospective, placebo-controlled studies are necessary.